Border-Associated Macrophages: From Embryogenesis to Immune Regulation

Area of Science:

• Neuroscience
• Immunology
• Cell Biology

Background:

• Border-associated macrophages (BAMs) are critical for brain homeostasis and disease response.
• Their origins, characteristics, and functions in healthy and diseased brains require further elucidation.
• Advancing knowledge of BAMs is essential for understanding neuroinflammation and neurodegeneration.

Purpose of the Study:

• To review the ontogeny, replenishment, and regulation of BAMs.
• To highlight recent advancements in BAMs research using lineage tracing and fate-mapping.
• To examine the roles of BAMs in brain homeostasis, immune surveillance, and disease.

Main Methods:

• Literature review focusing on recent advancements in BAMs research.
• Analysis of lineage tracing and fate-mapping studies.
• Examination of transcriptomic heterogeneity and microenvironmental regulation of BAMs.

Main Results:

• BAMs originate from specific precursors and have distinct replenishment mechanisms.
• Microenvironmental factors significantly regulate BAMs' characteristics and functions.
• Transcriptomic heterogeneity reveals diverse BAM subpopulations with specialized roles.
• BAMs are crucial for immune surveillance and responding to brain injury and neurodegeneration.

Conclusions:

• Further research is needed to clarify the dynamic interplay between BAMs and the brain microenvironment.
• Understanding BAMs will resolve controversies and identify therapeutic targets for neurological disorders.
• This work pushes the boundaries of neuroscience in understanding brain immunity and disease.